The right answer is Some sugars are used as building materials (plastic role).
Carbohydrates have 2 roles:
* Energy role
Carbohydrates, essential for the functioning of muscles and the brain, are the energy source that is the fastest to be used by the body and are involved in protein anabolism. Carbohydrates therefore have an essentially energetic role. Brought by the diet, they are degraded into glucose which will be distributed in the body. Part of it is stored as glycogen in the liver and muscles which will serve as a reserve.
* Plastic role
Some carbohydrates have a role called "constitution". They go into the composition of fundamental tissues of the body: cartilage, nucleic acids, mucus, antigenic substances.